TBX5 genetic testing validates strict clinical criteria for Holt-Oram syndrome

Holt-Oram syndrome (HOS) is an autosomal dominant heart-hand syndrome characterized by congenital heart disease (CHD) and upper limb deformity, and caused by mutations in the TBX5 gene. To date, the sensitivity of TBX5 genetic testing for HOS has been unclear. We now report mutational analyses of a nongenetically selected population of 54 unrelated individuals who were consecutively referred to our center with a clinical diagnosis of HOS. TBX5 mutational analyses were performed in all individuals, and clinical histories and findings were reviewed for each patient without reference to the genotypes. Twenty-six percent of the complete cohort was shown to have mutations of the TBX5 gene. However, among those subjects for whom clinical review demonstrated that their presentations met strict diagnostic criteria for HOS, TBX5 mutations were identified in 74%. No mutations were identified in those subjects who did not meet these criteria. Thus, these studies validate our clinical diagnostic criteria for HOS including an absolute requirement for preaxial radial ray upper limb malformation. Accordingly, TBX5 genotyping has high sensitivity and specificity for HOS if stringent diagnostic criteria are used in assigning the clinical diagnosis.     

Mutations in the EGF-CFC Gene Cryptic Are an Infrequent Cause of Congenital Heart Disease

Cryptic (CFC1), a member of the epidermal growth factor–Cripto/FRL-1/Cryptic (EGF–CFC) gene family, is involved in the evolutionarily conserved establishment of left–right lateral asymmetry. Inactivation of Cfc1 in mice results in laterality defects and complex cardiac malformations. Similarly, mutations in the human CFC1 gene have been identified in patients with heterotaxy syndrome. The cardiac defects in humans resemble those in mice lacking Cfc1. We postulated that some patients with isolated cardiac malformations could also have mutations in the CFC1 gene. Our analysis of the CFC1 gene in 167 patients with congenital heart disease revealed a novel A145T missense variant in 3 patients with type II atrial septal defect. Furthermore, we found the previously characterized R78W polymorphism in another patient with type II atrial septal defect. However, the A145T sequence alteration was also identified in 3 controls, suggesting that this variant is a polymorphism. We conclude that CFC1 variants could be a rare cause of congenital heart disease in patients without laterality defects.     

NKX2.5基因和TBX5基因在先天性心脏病试管婴儿中的突变检测

目的探讨患先天性心脏病的试管婴儿与自然受孕儿间是否存在NKX2.5基因和TBX5基因突变差异。方法应用聚合酶链反应结合DNA测序技术,对68例试管婴儿先天性心脏病患儿和98例自然受孕先天性心脏病患儿的NKX2.5基因编码区1、2和TBX5基因编码区4、5、8进行突变检测。结果在患先天性心脏病的试管婴儿与自然受孕儿中,均发现NKX2.5基因编码区1中第63位碱基发生突变(c.63AG),该位点基因型及等位基因频率的分布在两组间差异无统计学意义。NKX2.5基因编码区2和TBX5基因编码区4、5、8未检测到突变。结论先天性心脏病的试管婴儿与自然受孕儿间NKX2.5基因和TBX5基因突变无差异,推测辅助生殖技术并未引起NKX2.5基因和TBX5基因突变。     

Congenital Cardiac Defects: A Possible Association of Aminopterin Syndrome and In Utero Methotrexate Exposure?

Folate antagonist are chemotherapeutic agents used in many neoplastic, autoimmune, and inflammatory disorders. The first suggestions that folic acid antagonists were teratogenic in humans were based on reports of failed terminations in mothers given aminopterin in the first trimester. Newborns who survived after aminopterin exposure were noted for years to have defects of the neural tube, skull, or limbs. There is now a well-defined syndrome of congenital anomalies associated with the use of aminopterin. The aminopterin syndrome consists of cranial dysostosis, hypertelorism, anomalies of the external ears, micrognathia, limb anomalies, and cleft palate. The use of aminopterin has now fallen out of favor. Methotrexate is a folate antagonist that is now used more frequently. A similar pattern of malformations has been found in fetuses exposed to methotrexate. If used during pregnancy, it can cause congenital malformations or fetal death. A consistent association between methotrexate exposure and cardiac, renal, or gastrointestinal malformations has not been reported. We report two patients who presented with classic features of aminopterin syndrome combined with significant congenital cardiac malformations after first-trimester in utero methotrexate exposure. Both of these patients survived to undergo corrective cardiac surgery.     

Gene expression in pediatric heart disease with emphasis on conotruncal defects

Developmental abnormalities of the heart are the underlying cause of many congenital heart malformations. The embryological development of the integrated cardiovascular tissue is the result of multiple tissue and cell-to-cell interactions involving temporal and spatial events under genetic control. Recent technological advances, like microarray analysis of gene expression, are providing new tools to aid in deciphering the complex networks of gene expression that regulate cardiac development. Here, we review our current understanding of the genetics of congenital heart disorders with emphasis on gene expression studies and report preliminary data from infants with conotruncal defects. We report our microarray analysis showing over- and underexpression of individual genes and gene network interactions from dysplastic pulmonic tissue from two infants with tetralogy of Fallot compared with normal pulmonic tissue from an unaffected control infant.     

转录因子在先天性房室隔缺损遗传学机制中的作用

先天性房室隔缺损是一种累及心脏房室瓣和房室间隔的先天性心脏病.心脏转录因子在心脏瓣膜发育及房室间隔的形成方面起重要作用,目前已知转录因子GATA4、NKX2.5、TBX5、ZIC3可能参与了房室隔缺损的发病机制,它们的表达异常或功能变化可能导致房室瓣膜及间隔的发育异常.     

转录因子在先天性房室隔缺损遗传学机制中的作用

先天性房室隔缺损是一种累及心脏房室瓣和房室间隔的先天性心脏病.心脏转录因子在心脏瓣膜发育及房室间隔的形成方面起重要作用,目前已知转录因子GATA4、NKX2.5、TBX5、ZIC3可能参与了房室隔缺损的发病机制,它们的表达异常或功能变化可能导致房室瓣膜及间隔的发育异常.     

Cardiac problems in genetic syndromes

Congenital heart disease affects around 0.7% of liveborn infants and is the most frequent cause of death from congenital malformations. This review will consider some of the commoner genetic syndromes associated with congenital heart disease, the spectrum of cardiac defects observed in them and the associated features and comorbidities that may impact on the outcomes of cardiac surgery.     

Variable clinical expression of Holt-Oram syndrome in three generations

Holt-Oram syndrome is a distinct autosomal dominant entity presenting with upper limb defects and cardiac abnormality. No correlation between the severity of the heart and the limb defects has been established. Here we report variable clinical expression of Holt-Oram syndrome in three generations. The grandfather presented with typical upper limb defects: phocomelia of arms with three digits on each hand, congenital heart defect and narrow shoulders. His son manifested cardiac conduction disturbance with no congenital heart or skeletal defect. The granddaughter showed ventricular septal defect and moderate radial deviations of both hands with no obvious hypoplasia of the extremities. Clinical data of the presented family suggests lack of penetrance with respect to skeletal and structural cardiac abnormalities in the Holt-Oram syndrome.     

Holt-Oram综合征的诊断与治疗:附14例报告

为了探讨Holt-Oram综合征的临床特点和治疗方法，对1990年1月-2000年5月收治的14例患者进行回顾性分析。14例患者的心脏改变均通过心脏超声心动图、心电图、X线胸片诊断，其中10例复杂或复合先心病患儿通过心导管检查确诊；肢体畸形主要靠体检和X线检查。2例在学龄前选取心导管介入治疗，1例重度肺高压患儿在5个月时行外科手术，1例法洛四联症合并缺氧发作患儿在15个月时行根治手术，另有3例在学龄前期行根治手术均获得较好疗效。治疗方案和手术时机的选择主要取决于先心病的严重程度；肢体畸形可以行外科矫形手术。     

Cardiac abnormalities and nonimmune hydrops fetalis: a coincidental, not causal, relationship

Few conditions associated with nonimmune hydrops fetalis have had a demonstrable causal relationship. Congenital heart disease is often said to be a cause of nonimmune hydrops fetalis and antenatal closure of the foramen ovale is the cardiac abnormality most frequently reported in association with hydrops. In order to examine the role of congenital heart disease in hydrops, and, in particular, that of antenatal closure of the foramen ovale, we reviewed all autopsy cases with hydrops fetalis over an 11 year period and compared cardiac anomalies with those of nonhydropic controls. The incidence of various congenital heart malformations was not significantly different among these groups, suggesting that factors in addition to cardiac anomalies must be considered in the pathogenesis of nonimmune hydrops fetalis.     

The influence of congenital heart disease on survival of infants with oesophageal atresia

OBJECTIVE: To examine the prevalence of congenital heart disease in babies with oesophageal atresia and its influence on outcome. DESIGN: Retrospective analysis. SETTING: The resident population of one health region. RESULTS: A total of 153 babies with oesophageal atresia were identified from 509 975 live births (0.30 per 1000); 26 (17%) had cardiac defects. Survival of babies with normal hearts was 97%, 97%, and 95% at one week, one month, and one year. Survival of babies with congenital heart disease was 85%, 85%, and 67% at one week, one month, and one year, but only one of ten deaths was the result of the congenital heart disease. The remaining deaths were due to other congenital malformations, respiratory disease, or chromosome abnormalities. CONCLUSIONS: There is a high prevalence of congenital heart disease in babies with oesophageal atresia. Congenital heart disease is associated with a higher mortality in oesophageal atresia but it is not the cause of it.     

Cardiac Abnormalities and Nonimmune Hydrops Fetalis: a Coincidental, Not Causal, Relationship

Few conditions associated with nonimmune hydrops fetalis have had a demonstrable causal relationship. Congenital heart disease is often said to be a cause of nonimmune hydrops fetalis and antenatal closure of the foramen ovale is the cardiac abnormality most frequently reported in association with hydrops. In order to examine the role of congenital heart disease in hydrops, and, in particular, that of antenatal closure of the foramen ovale, we reviewed all autopsy cases with hydrops fetalis over an 11 year period and compared cardiac anomalies with those of nonhydropic controls. The incidence of various congenital heart malformations was not significantly different among these groups, suggesting that factors in addition to cardiac anomalies must be considered in the pathogenesis of nonimmune hydrops fetalis.     

Congenital heart disease: Genetic causes and developmental insights

The genetic basis of congenital heart disease, an important form of cardiovascular disease in the young, is being increasingly recognized. Using a combination of human molecular genetic studies and developmental models in several animal species, significant advances in the understanding of normal cardiac development and the pathogenesis of cardiac malformations are being made. Here we review congenital heart disease due to single gene defects identified by human genetic studies, genotype–phenotype correlations and insights into pathogenesis resulting from studies in model systems. The future promises that these complementary approaches will inform clinical management and provide the means to develop new diagnostic and therapeutic approaches to congenital heart disease.     

The Impact of Fetal Echocardiography

Fetal echocardiography has impacted the fetus with congenital heart disease in many important ways. Advances in fetal echocardiography have allowed for more accurate and earlier detection of cardiac abnormalities. In turn, the prenatal diagnosis of cardiac abnormalities has improved the care and outcome of selected fetuses with severe cardiac malformations or arrhythmias. Fetal echocardiography has improved the understanding of the development and evolution of congenital heart disease in utero, and it may serve a role in identifying candidates for prenatal intervention. The prenatal diagnosis of congenital heart disease has allowed for better counseling and preparation of families regarding the anticipated prenatal development of the fetus as well as the expected postnatal management plans and prognosis. This article reviews the impact of fetal echocardiography in these and other areas.     

High Association of Congenital Heart Disease with Indirect Inguinal Hernia

We evaluated 103 patients with indirect inguinal hernia (IIH) for the association of congenital heart disease by echocardiography. Congenital cardiac abnormalities were recognized in 32% of patients with inguinal hernia, which is significantly higher than that reported in a population-based study in Turkey and other population-based studies. Ventricular septal defect and valvular anomalies are the most frequently detected malformations. Our findings suggest that screening for congenital hearth disease is necessary in children with indirect inguinal hernia.     

围孕期营养因素与先天性心脏病发病的关系

先天性心脏病是人体在胚胎发育时期受各种因素影响导致心脏及血管发育异常的先天性畸形.先天性心脏病是人类最常见的先天畸形,是导致婴儿发病和病死的重要原因.即使可以经过外科手术矫治畸形,先天性心脏病患儿也要面临各种手术并发症甚至疾病复发的风险,给社会带来巨大的经济压力.目前普遍认为先天性心脏病的发生受遗传因素和环境因素的共同影响.近年来围孕期营养因素与先天性心脏病的发病关系成为研究热点.研究结果显示,叶酸及其他围孕期营养素与先天性心脏病的发生有密切关系,围孕期母亲适当补充这些营养素可降低子代先天性心脏病的发生风险.该文就叶酸、维生素A、锌、维生素B、维生素E围孕期关键营养因素与先天性心脏病的关系,从病因、发病机制及预防方面进行综述,为疾病的预防提供基础.